Forward and reverse scanning-type display device

Abstract

Disclosed herein is a forward and reverse scanning-type display device using a diffractive optical modulator. The display device includes a light source system, one or more illumination optical units, a diffractive optical modulator, a projection and scanning optical unit and a display electronic system. The light source system radiates light. The illumination optical units convert the light into linear incident light. The diffractive optical modulator modulates the linear incident light into linear diffracted light in response to driving signals. The projection and scanning optical unit creates an image by repeatedly and alternately scanning the linear diffracted light on a screen in a first direction and in a reverse direction. The display electronic system outputs the driving signals to the diffractive optical modulator in intervals for the scanning in the first and reverse directions and, thereby, controls the diffractive optical modulator such that the diffractive optical modulator can create linear diffracted light in the intervals for the scanning in the first and reverse directions.

1 . A forward and reverse scanning-type display device using a diffractive optical modulator, comprising: 
 a light source system for creating and radiating light;    one or more illumination optical units for converting the light, which is emitted from the light source system, into linear incident light;    a diffractive optical modulator for modulating the linear incident light, which is emitted from the illumination optical units, into linear diffracted light in response to driving signals;    a projection and scanning optical unit for creating an image by repeatedly and alternately scanning the linear diffracted light, which is emitted from the diffractive optical modulator, on a screen in a first direction and in a reverse direction; and    a display electronic system for outputting the driving signals to the diffractive optical modulator in intervals for the scanning in the first and reverse directions and, thereby, controlling the diffractive optical modulator such that the diffractive optical modulator can create linear diffracted light, including image information, in the intervals for the scanning in the first and reverse directions.    
   
   
       2 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein the projection and scanning optical unit comprises a scanner that scans the scanning line on the screen in the first direction, scans the scanning line in the reverse direction, and repeats the above operations, thereby creating an image on the screen.  
   
   
       3 . The forward and reverse scanning-type display device as set forth in  claim 2 , wherein the display electronic system comprises a scanning control unit that controls the scanner such that a speed at which the linear diffracted light passes through a specific point of the screen during the scanning in the first direction is similar to a speed at which the linear diffracted light passes through the point of the screen during the scanning in the reverse direction.  
   
   
       4 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein the display electronic system comprises: 
 an image input unit for receiving image data from outside;    memory for storing the image data input from the image input unit;    an image data output unit for sequentially reading and outputting the image data from the memory from a first column to a last column for the intervals for the scanning in the first direction, and sequentially reading and outputting the image data from the last column to the first column in the intervals for the scanning in the reverse direction; and    an optical modulator driving circuit for providing driving signals based on the image data which is output from the image data output unit, to the diffractive optical modulator.    
   
   
       5 . The forward and reverse scanning-type display device as set forth in  claim 4 , wherein the display electronic system further comprises an image pivot unit that converts the image data, which is input in a lateral direction, into image data, which is arranged in a vertical direction, by performing data transposition such that the image data, which is input to the image input unit and arranged in the lateral direction, is transposed into the image data, which is arranged in the vertical direction, and stores the vertically arranged image data in the memory.  
   
   
       6 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein the diffracted light emitted from the diffractive optical modulator is diffracted light having a plurality of diffraction orders; 
 further comprising a filter unit that is located behind the diffractive optical modulator and passes light having a specific diffraction order, which belongs to the diffracted light having the plurality of diffraction orders, therethrough.    
   
   
       7 . The forward and reverse scanning-type display device as set forth in  claim 6 , wherein the filter unit comprises: 
 a Fourier lens for separating the diffracted light, which is emitted from the diffractive optical modulator and has the plurality of diffraction orders, according to diffraction order; and    a filter for selecting the diffracted light having a specific diffraction order from the diffracted light having the plurality of diffraction orders that is passed through the Fourier lens, and passing the diffracted light having a specific diffraction order therethrough.    
   
   
       8 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein: 
 the light source system comprises a red light source, a green light source and a blue light source; and    the display electronic system comprises a light source control unit that controls the light source system such that red light, green light and blue light are sequentially output.    
   
   
       9 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein: 
 the light source system comprises a red light source, a green light source and a blue light source; and    the display electronic system comprises a light source control unit that controls the light source system such that red light, green light and blue light are sequentially emitted;    further comprising a color wheel that is located behind the light source system and sequentially passes the red light, the green light and the blue light therethrough.    
   
   
       10 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein the first direction is a lateral direction of the screen.  
   
   
       11 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein the first direction is a vertical direction of the screen.  
   
   
       12 . The forward and reverse scanning-type display device as set forth in  claim 1 , wherein the diffractive optical modulator comprises: 
 a substrate;    a plurality of first reflection members arranged to form an array, supported by the substrate, spaced apart from the substrate at center portions thereof to ensure a space, provided with reflection surfaces at upper portions thereof to reflect the incident light, and each provided with at least one open hole to pass the incident light therethrough;    a second reflection member located between the substrate and the first reflection members to be spaced apart from the first reflection members so as to ensure a space, and provided with a reflection surface to reflect light passed through and incident from the open holes of the first reflection members; and    a plurality of actuation means for varying an amount of the diffracted light, which is formed by the light reflected by the first reflection members and the second reflection member, by moving the center portions of the first reflection members toward or away from the substrate in response to the driving signals when the driving signals are input from the display electronic system.    
   
   
       13 . The forward and reverse scanning-type display device as set forth in  claim 12 , wherein each of the first reflection members comprises a plurality of open holes that are arranged in a direction identical to a direction that crosses the substrate.